Magnetic recording media, magnetic heads and magnetic read-write apparatus using the same

ABSTRACT

A magnetic recording medium wherein, when the axis of easy magnetization of the magnetic recording medium for magnetically recording information by means of a magnetic head is projected onto a surface of the magnetic recording medium, the axis projected onto the surface of the magnetic recording medium exists so as to be unidirectionally inclined with respect to the direction of a track on which information is to be recorded, whereby, by using the magnetic recording medium, there can be provided a magnetic head and a magnetic read-write apparatus greatly improved in longitudinal recording density.

This is a division of application Ser. No. 08/794,709 filed Feb. 4,1997, now U.S. Pat. No. 5,875,082

BACKGROUND OF THE INVENTION

The present invention relates to a magnetic recording mode for improvingsurface recording density greatly and particularly to magnetic recordingmedia, magnetic heads and a magnetic read-write apparatus using the samefor achieving high-density magnetic recording.

Recently, improvement of recording density in the field of magneticrecording, particularly in magnetic recording disks, is remarkable andresearches and developments are being hastened to achieve ahigher-density read-write apparatus. The recording mode used in magneticrecording disks at present is a longitudinal magnetic recording mode inwhich recorded magnetization is directed to a track. In order to improvethe recording density more greatly, a perpendicular magnetic recordingmode free from self-demagnetization even in high linear recordingdensity has been proposed or researched eagerly to be used in magneticrecording media (Iwasaki and Ouchi: IEEE Trans. Magn., MAG-14, 849(1978), and so on) but the mode has been not yet put into practical use.

On the other hand, an obliquely magnetic recording mode free fromself-demagnetization even in high linear recording density as well asthe perpendicular magnetic recording mode is used in the field of VTRsin which longitudinal magnetic recording is mainly carried out.Particularly, as for a recording medium, an obliquely deposited Co—Nitape has been put into practical use as a high-band 8 mm VTR magnetictape, and a tape improved in characteristic is expected to be used alsoas a small-size digital VTR tape in the future (Yoshida, Shinohara andOdagiri: Journal of The Magnetics Society of Japan, Vol. 18, No. S1,439(1994)).

In a magnetic recording using a ring type magnetic head used in magneticrecording at prevent, the fact that the obliquely magnetic recordingmode is more preferable in high-density recording than the longitudinalmagnetic recording mode and the perpendicular magnetic recording modehas been confirmed by the simulation by Tagawa et al in TohokuUniversity (Tagawa, Shimizu and Nakamura: Journal of The MagneticSociety of Japan, Vol. 15, No. S2,827 (1991)). Also in magneticrecording disks, it is expected that recording density will be improvedremarkably by use of the obliquely magnetic recording mode.

In the case of a magnetic tape, a magnetic recording medium having anaxis of-easy magnetization inclined to the recording direction can beformed by obliquely depositing, for example, a ferromagnetic Co—Nialloy. In the case of a magnetic disk, it is theoretically possible toform a magnetic recording layer having an axis of easy magnetizationinclined circumferentially on a circular substrate as disclosed also inJP-A-58-128023, but it is difficult to mass-produce such magnetic disksas products. Accordingly, to put magnetic recording disk devices usingan obliquely magnetic recording mode into practical use has beenconsidered to be almost impossible.

SUMMARY OF THE INVENTION

The present invention is intended to solve above-mentioned problems. Afirst object of the present invention is therefore to propose a magneticrecording mode for realizing an obliquely magnetic recording mode in amagnetic recording disk so as to provide a high-density large-capacitymagnetic read-write apparatus which has been never provided. A secondobject of the present invention is to provide a magnetic recordingmedium suitable for realizing an obliquely magnetic recording mode. Athird object of the present invention is to provide a magnetic headsuitable for realizing an obliquely magnetic recording mode.

In order to apply an obliquely magnetic recording mode to a magneticrecording disk, conventionally, it was considered to make the axis ofeasy magnetization in a magnetic recording layer formed on a circularsubstrate inclined circumferentially. But, although it was possibletheoretically, the process how to produce the magnetic recording mediumwas hard in terms of mass-production so that the magnetic recordingmedium could not be realized.

Therefore, the inventors of the present application have made researchesactually upon the thought that obliquely magnetic recording can becarried out on a magnetic recording disk by using a magnetic recordingmedium having a radially inclined axis of easy magnetization of amagnetic recording layer formed on a circular substrate and by using amagnetic head for effectively generating a magnetic field radially. As aresult, the present inventors have found that not only obliquelymagnetic recording can be made but also extremely high recording densitycompared with the conventional longitudinal magnetic recording mode canbe achieved.

That is, the above-mentioned first object of the present invention isachieved by performing recording, for example, by using a medium havingan axis of easy magnetization inclined in the direction of the radius ofa circular substrate and by using a ring type magnetic head having a yawangle not smaller than 15 degrees. The second object is achieved, forexample, by forming a medium structure in which the axis of easymagnetization is inclined in the direction of the radius of a circularsubstrate. The third object of the present invention is achieved, forexample, by forming a structure in which a gap portion of a magnetichead is largely inclined with respect to the circumferential directionof a circular recording substrate to its radial direction.

Incidentally, in the process of researches for the present invention,the present inventors have found that read-write can be madesufficiently even in the case where a mode in which the axis of easymagnetization of a medium is projected in a direction perpendicular tothe direction of relative movement between a magnetic head and themedium and the direction of head magnetic field is suitably inclined isapplied to a magnetic recording tape, similarly to the case of theaforementioned magnetic recording disk. The present inventors furtherhave found that, even in either case of a magnetic recording disk or amagnetic recording tape sufficiently high recording density can beachieved not only when the axis of easy magnetization of the medium isperpendicular to the direction of the relative movement between themagnetic head and the medium but also when the axis of easymagnetization of the medium is inclined suitably with respect to thedirection of the relative movement between the magnetic head and themedium.

Further, the present inventors have applied a mode, in which a neutralperiod is provided without making inversion of the polarity of arecording current supplied to the recording magnetic head when therecording current is to be inverted, to the relative positional relationbetween the medium and the magnetic head. As a result, the presentinventors have found that the output/medium noise (S/N) ratio can beimproved greatly to the same degree as in the case of ordinary obliquemagnetic recording so that the recording density can be improved.

FIG. 1 shows an example of the structure of a magnetic recording mediumand a magnetic head for explaining a magnetic recording mode accordingto the present invention in which the axis of easy magnetization of themagnetic recording medium exists in a plane perpendicular to therecording track direction. The portion encircled with broken lines inFIG. 1 is a partially enlarged view to show an inclination relationbetween a recording track and magnetic poles.

First, the axis of easy magnetization 120 of a magnetic recording layer110 of a magnetic recording medium 100 exists in a plane perpendicularto a recording track 130. Next, a gap portion 220 formed by two magneticpoles 210 and 211 of a magnetic head 200 is disposed to be largelyinclined with respect to the recording track direction 130 so that anintensive magnetic field is generated in a direction which is inclinedfrom the recording track direction. Accordingly, the magnetic fieldgenerated from the head 200 has effectively intensive magnetic fieldcomponents also in the direction of the axis of easy magnetization 120of the magnetic recording medium 100. In such a configuration asdescribed above, magnetization of the medium in which the axis of easymagnetization 120 exists in a plane perpendicular to the recording track130 is recorded by the intensive recording magnetic field components ina direction perpendicular to the recording track direction.

Because it has been found that, though it could not be thought of so farfrom the common sense, sufficient magnetic recording can be made even inthe case where the axis of easy magnetization is perpendicular to therecording track, it is apparent that recording can be carried out in thecase where the axis of easy magnetization of the medium projected onto asurface of the magnetic recording medium is inclined suitably withrespect to the direction of recording track. Incidentally, though thereason is not apparent, it has become clear, from the result of theinventors' researches, that the case where the axis of easymagnetization of the medium projected onto the surface of the magneticrecording medium is inclined suitably with respect to the direction ofrecording track is rather preferable in terms of high S/N andhigh-density recording than the case where the axis of easymagnetization of the medium projected onto the surface of the magneticrecording medium is coincident with the direction of recording track.

Incidentally, in the field of VTRs, for example, because of a helicalscan mode, the direction of relative movement between the magnetic headand the magnetic recording medium is slightly different from thedirection of the axis of easy magnetization of the medium projected ontothe surface of the medium, while the direction of relative movement issubstantially near to the direction of the axis of easy magnetization ofthe medium projected onto the surface of the medium. Further, in thefield of VTRs, an azimuth recording mode, in which a relative gap angle(azimuth) between two heads used for recording and reproducing isinclined in advance by ±θ to reduce cross-talk by using azimuth loss, isemployed in order to eliminate a guard band between tracks to therebyimprove track density. If the axis of easy magnetization of the mediumis projected onto the surface of the medium, however, the direction ofprojection exists at an angle near to the recording track direction. Incontrast thereto, in the present invention, when the axis of easymagnetization of the medium is projected onto the surface of the medium,the direction of projection is inclined largely with respect to thedirection of recording track. That is, the present invention isessentially different from the conventional case regardless of thedirection of the gap of the magnetic head.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a view showing a magnetic recording medium and a magnetic headaccording to the present invention;

FIG. 2 is a conceptual view of an obliquely incident sputtering methodfor producing the magnetic recording medium according to the presentinvention;

FIG. 3 is a graph showing an example of the magnetization curve of themagnetic recording medium according to the present invention;

FIG. 4 is a view showing an example of the model of the magnetic headhaving surfaces opposite to the recording medium according to thepresent invention;

FIG. 5 is a graph showing examples of read-write characteristicsmeasured with the yaw angle of the magnetic head set to be 0 degree uponmedia different in the angle between the axis of easy magnetizationprojected onto a substrate surface and the tracking direction;

FIG. 6 is a graph showing examples of read-write characteristicsmeasured with the yaw angle of the magnetic head set to be 15 degreesupon media different in the angle between the axis of easy magnetizationprojected onto a substrate surface and the tracking direction; and

FIG. 7 is a graph showing examples of read-write characteristicsmeasured with the yaw angle of the magnetic head set to be 30 degreesupon media different in the angle between the axis of easy magnetizationprojected onto a substrate surface and the tracking direction.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Examples according to the present invention will be described below.

EXAMPLE 1

As shown in FIG. 2 which is a conceptual view, a magnetic recordingmedium according to the present invention was produced by an obliquelyincident sputtering method. A sputtering apparatus the same as that usedat present for producing longitudinal magnetic recording media was used,in which a circular aperture 300 was provided between a circular sputtertarget 400 and a circular substrate 111 so that when volumetricparticles 402 were flown from the target 400 onto the substrate 111 bysputtering, the components which were flown in the direction of theradius of the substrate 11 from a sputter particle high-densitygenerating region 401 concentrically existing on a surface of the target400 were made to deposit. In such an arrangement, Ti as an undercoat ofa magnetic recording layer was formed with a thickness of 50 nm and aCo—Cr—Ta alloy as the magnetic recording layer was formed with athickness of 100 nm thereon. Incidentally, the Co—Cr—Ta alloy as themagnetic recording layer was formed in the same manner as generally usedfor forming longitudinal magnetic recording media. As a result, it wasconfirmed by-use of an X-ray diffraction method that both in the Tiundercoat and the Co—Cr—Ta film, the c-axis was inclined with respect toa direction perpendicular to the film surface to the direction of theradius thereof. Further, the magnetic recording medium thus producedaccording to the present invention was cut out and magnetization curvesin circumferential, radial and perpendicular directions with respect tothe substrate were measured. As a result, as shown in FIG. 3, themagnetization curve in the circumferential direction was inclined toform a narrow hysteresis curve 1133, the magnetization curve in theradial direction was slightly inclined but good in squareness to form alarge hysteresis curve 1131, and the magnetization curve in theperpendicular direction was good in squareness to form a largehysteresis curve 1132. From such a fact, it is considered that the axisof easy magnetization of the thus formed magnetic recording medium isinclined radially with respect to the direction perpendicular to thefilm surface and that the axis of hard magnetization is formedrelatively in the direction of the circumference.

Further, as a first comparative example, a Cr undercoat with a thicknessof 50 nm was formed by using a sputtering apparatus before theattachment of the circular aperture and a thickness of 20 nm was formedthereon from the same composition as the Co—Cr—Ta alloy film accordingto the present invention to thereby form a longitudinal magneticrecording medium. As a second comparative example, a Ti undercoat with athickness of 50 nm was formed by using a sputtering apparatus before theattachment of the circular aperture and a thickness of 100 nm was formedthereon from the same composition as the Co—Cr—Ta alloy to thereby forma perpendicular magnetic recording medium.

FIG. 4 is a model view showing the magnetic head having surfacesopposite to the recording medium according to the present invention. Inthis example, a magnetic head was produced in the same process as thatused for producing a thin-film head currently used for a magneticrecording disk, and a slider 201 was cut out obliquely so that the gapportion 220 was inclined by 60 degrees with respect to a recording trackdirection 130, that is, the yaw angle 240 was established to be 60degrees. Incidentally, for comparison between the longitudinal recordingand perpendicular recording, the same thin-film recording head wasproduced by cutting out the slider 201 at an ordinary angle so that thegap portion 220 was opposite to the recording track direction 130, thatis, the yaw angle was established to be 0 degree.

Thus, head media for oblique recording, longitudinal recording andperpendicular recording were produced respectively and the read-writecharacteristics thereof were evaluated and compared. Incidentally,recording at the yaw angle of 60 degrees was compared with recording atthe yaw angle of 0 degree upon the assumption that the relative speed ofthe head-medium was substantially equal to the cosine of 60 degrees (cos60°) so that the linear recording density was regarded as being thereciprocal of cos 60° (two times) and the measured values of reproducedoutput and noise were regarded as being doubled in the case where therelative speed and recording frequency of the head-medium were equalbetween the recordings at the yaw angles of 60 degrees and 0 degree.Table 1 shows results expressed in relative decibel value by referenceto the case where the yaw angle was 0 degree with respect to alongitudinally oriented medium.

TABLE 1 Media type Yaw angle S_(1kFCI) S_(150kFCI) N_(150kFCI)S/N_(150kFCI) longitudinal- 0 0 0 0 0 ly oriented degree (reference)(reference) (reference) (reference) medium perpendicu- 0 −0.5 +0.3 −2.1+2.4 larly orient- degree ed medium obliquely 60 +2.5 +6.3 −3.5 +9.8oriented degrees medium

As shown in Table 1, it is found that not only he oblique recording ishigh both in reproduced output and in recording resolution but also theoblique recording is low in medium noise and is improved greatly inreproduced output/medium noise ratio in the high-density region.Further, when, for example, the yaw angle is 60 degrees as shown in thisexample, the effective write track width can be reduced to a halfcompared with the case where the yaw angle is 0 degree. Accordingly, ithas been confirmed theoretically, as shown in this example, thatlongitudinal recording density several times as much as the existinglongitudinal recording density can be achieved by using a disk mediumhaving the axis of easy magnetization inclined radially with respect tothe direction perpendicular to the film surface and by using a writehead having the yaw angle established to be large.

If the axis of easy magnetization of the magnetic recording medium onthe circular substrate is projected onto the substrate surface becauseof the condition of geometrical arrangement of the circular target 400,the circular aperture 300 and the substrate 111, the unevenness of thesputter particle high-density generating region 401 generated on thesurface of the target 400, and so on, when the recording medium havingthe axis of easy magnetization inclined radially with respect to thedirection perpendicular to the film surface is formed, there is a regionin which the projected axis of the easy magnetization exists between theradial direction and the circumferential direction. The read-writecharacteristics of such a region was evaluated. As a result,sufficiently high recording resolution and reproduced output/mediumnoise ratio were obtained not only in the case where the yaw angle wasformed in the write head as described above but also in the case wherethe yaw angle was set to be 0 degree.

EXAMPLE 2

Because good recording resolution and reproduced output/medium noiseratio were obtained when the axis of easy magnetization projected ontothe substrate surface existed between the direction of the radius of thecircular substrate and the direction of the circumference thereof, therelation between the direction of the axis of easy magnetization and theread-write characteristics was examined by using the obliquely orienteddeposition tape.

For the obliquely oriented deposition tape, a magnetic recording layerhaving a thickness of 2 μm was formed by depositing Co in the atmosphereof introduced oxygen by using the same winding type film-formingapparatus as used for producing the obliquely deposition tape availableon the market as an 8 mm VTR tape. If the axis of easy magnetizationobliquely oriented with respect to the substrate surface in thismagnetic recording layer in the same manner as the available obliquedeposition tape was projected onto the substrate surface, the projectedaxis existed in the direction of taking-up of the substrate. Samples cutout at various angles with respect to the deposition film prepared asdescribed above were set in a magnetic recording tape read-writeevaluation apparatus to examine the characteristics of the samples. Thecut-off angles are selected to be an angle (0 degree as a referencevalue) parallel to the taking-up direction of the substrate, 10 degrees,20 degrees, 30 degrees, 45 degrees, 60 degrees, 75 degrees and 90degrees in the case where the cut-off angle is perpendicular to thetaking-up direction of the substrate. The evaluation of the read-writecharacteristics was made by measuring reproduced output and medium noiseat the time of recording in the linear recording density of 100 kFCI andperforming relative comparison.

First, the evaluation result in the case where the gap portion of themagnetic head is made to be perpendicular to the recording trackdirection, that is, in the case where the yaw angle is 0 degree, isshown in FIG. 5. Although the reproduced output showed a tendency todecrease when the angle between the axis of easy magnetization projectedonto the substrate surface and the tracking direction shifted widely,good characteristic was exhibited unexpectedly in the case where theangle shifted in a range of from 10 degrees to 20 degrees. On the otherhand, the medium noise was reduced greatly when the angle between theaxis of easy magnetization projected onto the substrate surface and thetracking direction became 30 degrees or higher. As a result, it wasfound that the reproduced output/medium noise ratio was improved whenthe angle between the axis of easy magnetization projected onto thesubstrate surface and the tracking direction was in a range of from 20degrees to 45 degrees compared with the case where the angle between theaxis of easy magnetization projected onto the substrate surface and thetracking direction was 0 degree.

Then, read-write characteristics were evaluated by using the sametape-like recording samples in the condition that the yaw angle of themagnetic head was 15 degrees. The result is shown in FIG. 6. In thecase, because the highest reproduced output was obtained when the anglebetween the axis of easy magnetization projected onto the substratesurface and the tracking direction was 30 degrees, the reproducedoutput, medium noise and reproduced output/medium noise ratio wereexpressed by reference to those obtained when the angle between the axisof easy magnetization projected onto the substrate surface and thetracking direction was 30 degrees. The reproduced output was reduced ifthe angle between the axis of easy magnetization projected onto thesubstrate surface and the tracking direction was not smaller than 30degrees, but the reduction was small compared with the case where theyaw angle was 0 degree. On the other hand, in the sample in which theangle between the axis of easy magnetization projected onto thesubstrate surface and the tracking direction was not smaller than 30degrees, the medium noise was reduced greatly and, as a result, thehighest reproduced output/medium noise ratio was obtained in the casewhere the angle between the axis of easy magnetization projected ontothe substrate surface and the tracking direction was 60 degrees. It wasfurther found that a higher reproduced output/medium noise ratio wasobtained when the angle between the axis of easy magnetization projectedonto the substrate surface and the tracking direction was in a range offrom 30 degrees to 75 degrees compared with the case where the angle was0 degree.

Further, the read-write characteristics were evaluated by using the sametape-like recording samples in the condition that the yaw angle of therecording head was 30 degrees. The result is shown in FIG. 7. Also inthis case, because the highest reproduced output was obtained when theangle between the axis of easy magnetization projected onto thesubstrate surface and the tracking direction was 30 degrees, thereproduced output, medium noise and reproduced output/medium noise ratiowere expressed by reference to those in the case where the angle betweenthe axis of easy magnetization projected onto the substrate surface andthe tracking direction was 30 degrees. The reproduced output was reducedif the angle between the axis of easy magnetization projected onto thesubstrate surface and the tracking direction was not smaller than 30degrees, but the reduction was further smaller compared with the casewhere the yaw angle was 0 degree or 15 degrees. On the other hand, inthe sample in which the angle between the axis of easy magnetizationprojected onto the substrate surface and the tracking direction was notsmaller than 30 degrees, the medium noise was reduced greatly and, as aresult, the highest reproduced output/medium noise ratio was obtained inthe case where the angle between the axis of easy magnetizationprojected onto the substrate surface and the tracking direction was 75degrees. It was further found that a higher reproduced output/mediumnoise ratio was obtained when the angle between the axis of easymagnetization projected onto the substrate surface and the trackingdirection was in a range of from 45 degrees to 90 degrees compared withthe case where the angle was 0 degree. That is, even in the case wherethe angle was 90 degrees, the reproduced output medium noise was high.

It was apparent from the above description that a higher reproducedoutput/medium noise ratio was obtained when the angle between the axisof easy magnetization projected onto the substrate surface and thetracking direction was in a range of from 10 degrees to 45 degreescompared with the angle of 0 degree even in the case where the yaw angleof the magnetic head was 0 degree, and that a higher reproducedoutput/medium noise ratio was obtained when the angle between the axisof easy magnetization projected onto the substrate surface and thetracking direction was large by providing a yaw angle in the magnetichead.

EXAMPLE 3

On a disk substrate having a Parmalloy film provided as a highpermeability layer, a Ti film and a Co—Cr—Ta film were formed in thesame manner as in Example 1 so as to produce a disk having the axis ofeasy magnetization inclined radially with respect to the directionperpendicular to the film surface. Further, for comparison, a Ti filmand a Co—Cr—Ta film were formed on a disk substrate having the sameParmalloy film as described above by an ordinary sputtering method tothereby produce a disk having an axis of easy magnetization oriented tothe perpendicular direction.

With respect to the two kinds of disks thus produced, read-writecharacteristics were evaluated by using a single pole type head whilechanging the yaw angle. The reproduced output, medium noise andreproduced output/medium noise ratio in the case where recording wasmade in the condition of the linear recording density of 150 kFCI areshown in Tables 2, 3 and 4, respectively.

TABLE 2 (perpendicular (obliquely orient- magnetic recording ed magneticlay- yaw layer/high perme- er/high permeabil- angle ability layer) diskity layer) disk  0 degree 0 dB (reference) −2.4 dB 15 degrees −0.7 dB−0.7 dB 30 degrees −2.6 dB −0.9 dB 45 degrees −6.2 dB −1.5 dB

TABLE 3 (perpendicular (obliquely orient- magnetic recording ed magneticlay- yaw layer/high perme- er/high permeabil- angle ability layer) diskity layer) disk  0 degree 0 dB (reference) −3.5 dB 15 degrees −0.3 dB−4.5 dB 30 degrees −1.4 dB −4.7 dB 45 degrees −3.3 dB −5.1 dB

TABLE 4 (perpendicular (obliquely orient- magnetic recording ed magneticlay- yaw layer/high perme- er/high permeabil- angle ability layer) diskity layer) disk  0 degree 0 dB (reference) +1.2 dB 15 degrees −0.4 dB+3.8 dB 30 degrees −1.2 dB +3.8 dB 45 degrees −2.9 dB +3.6 dB

Incidentally, the value obtained when an ordinary perpendicular magneticrecording layer was used and the yaw angle was set to be 0 degree wasexpressed to be 0 dB as a reference value in comparison. Further, themeasured values of the read-write characteristics were expressed in theTables by using the values of reproduced output and medium noisemeasured by the head without any correction corresponding to the changeof the yaw angle as in Example 1.

As shown in Table 2, the disk having the magnetic recording layeroriented radially obliquely was low in the reproduced output comparedwith the disk using the ordinary perpendicular magnetic recording layerin the case where the yaw angle was 0 degree, but the disk having themagnetic recording layer oriented radially obliquely exhibited a higherreproduced output than the disk using the ordinary perpendicularmagnetic recording layer in the case where the yaw angle was not smallerthan 15 degrees.

On the other hand, as shown in Table 3, the disk having the radiallyobliquely oriented magnetic recording layer exhibited extremely lowermedium noise characteristic than the disk using the ordinaryperpendicular magnetic recording layer. As a result, it was apparentfrom Table 4 that the disk having the radially obliquely orientedmagnetic recording layer exhibited a higher reproduced output/mediumnoise ratio than the disk using the ordinary perpendicular magneticrecording layer even in the case where the yaw angle was 0 degree.

According to the present invention, oblique recording can be realized bymeans of a circular disk only by slightly changing a conventionalprocess of producing a medium and a head. Accordingly, the reproducedoutput/medium noise ratio, linear recording density and track densitycan be improved greatly compared with the conventional longitudinalrecording. Accordingly, the longitudinal recording density of themagnetic read-write apparatus can be improved greatly so that thepresent invention is useful for high-density recording.

What is claimed is:
 1. A magnetic read-write apparatus comprising: amagnetic recording medium, comprising a surface containing a trackextending in a direction, on which track information is to bemagnetically recorded, said magnetic recording medium having an axis ofeasy magnetization disposed in a plane, which plane is perpendicular toa plane of said surface and which makes an angle with the direction ofsaid track, which, when projected onto the plane of said surface isinclined with respect to the direction of said track on whichinformation is to be recorded; and means for magnetically recordinginformation on said magnetic recording medium.
 2. A magnetic read-writeapparatus comprising: a magnetic recording medium formed on a tape-likenon-magnetic substrate extending in a longitudinal direction andcontaining a track on which information is to be recorded extending insaid longitudinal direction, said medium having an axis of easymagnetization disposed in a plane, which plane is perpendicular to aplane of said surface and which makes an angle with the direction ofsaid track, which, when projected onto the plane of the surface of themagnetic recording medium is inclined with respect to said longitudinaldirection of said tape-like non-magnetic substrate; and means formagnetically recording information on said magnetic recording medium. 3.A magnetic read-write apparatus comprising: a magnetic recording medium,comprising a surface containing a track extending in a direction, onwhich track information is to be magnetically recorded, said magneticrecording medium having an axis of easy magnetization, disposed in aplane, which plane is perpendicular to a plane of said surface and whichmakes an angle with the direction of said track, which, when projectedonto the plane of said surface is inclined with respect to the directionof said track on which information is to be recorded; and a ring-typemagnetic head having a structure with a gap, said gap disposed so as tobe inclined in an angular range of from 15 degrees to less than 90degrees with respect to said direction of said track on whichinformation is to be recorded.
 4. A magnetic read-write apparatuscomprising: a magnetic recording medium formed on a tape-likenon-magnetic substrate extending in a longitudinal direction andcontaining a track on which information is to be recorded extending insaid longitudinal direction, said medium having an axis of easymagnetization disposed in a plane, which plane is perpendicular to aplane of said surface and which makes an angle with the direction ofsaid track, which, when projected onto the plane of the surface of themagnetic recording medium is inclined with respect to said longitudinaldirection of said tape-like non-magnetic substrate; and a ring-typemagnetic head having a structure with a gap, said gap disposed so as tobe inclined in an angular range of from 15 degrees to less than 90degrees with respect to said direction of said track on whichinformation is to be recorded.
 5. A magnetic read-write apparatuscomprising: a magnetic recording medium, comprising a surface containinga track extending in a direction, on which track information is to bemagnetically recorded, said magnetic recording medium having an axis ofeasy magnetization, disposed in a plane, which plane is perpendicular toa plane of said surface and which makes an angle with the direction ofsaid track, which, when projected onto the plane of said surface isinclined with respect to the direction of said track on whichinformation is to be recorded; and a ring-type magnetic head having astructure with a gap, said gap disposed so as to be inclined in anangular range of from 30 degrees to less than 90 degrees with respect tosaid direction of said track on which information is to be recorded. 6.A magnetic read-write apparatus comprising: a magnetic recording mediumformed on a tape-like non-magnetic substrate extending in a longitudinaldirection and containing a track on which information is to be recordedextending in said longitudinal direction, said medium having an axis ofeasy magnetization disposed in a plane, which plane is perpendicular toa plane of said surface and which makes an angle with the direction ofsaid track, which, when projected onto the plane of the surface of themagnetic recording medium is inclined with respect to said longitudinaldirection of said tape-like non-magnetic substrate; and a ring-typemagnetic head having a structure with a gap, said gap disposed so as tobe inclined in an angular range of from 30 degrees to less than 90degrees with respect to said direction of said track on whichinformation is to be recorded.
 7. A magnetic read-write apparatuscomprising: a magnetic recording medium formed on a circularnon-magnetic substrate through a soft magnetic recording layer of highpermeability, comprising a surface containing a track extending in adirection, on which track information is to be magnetically recorded,said magnetic recording medium having an axis of easy magnetization,disposed in a plane, which plane is perpendicular to a plane of saidsurface and which makes an angle with the direction of said track,which, when projected onto the plane of said surface is inclined withrespect to the direction of said track on which information is to berecorded; and a ring-type magnetic head having a structure with a gap,said gap disposed so as to be inclined in an angular range of from 15degrees to less than 90 degrees with respect to said direction of saidtrack on which information is to be recorded.
 8. A magnetic read-writeapparatus comprising: a magnetic recording medium formed on a circularnon-magnetic substrate through a soft magnetic recording layer of highpermeability, comprising a surface containing a track extending in adirection, on which track information is to be magnetically recorded,said magnetic recording medium having an axis of easy magnetization,disposed in a plane, which plane is perpendicular to a plane of saidsurface and which makes an angle with the direction of said track,which, when projected onto the plane of said surface is inclined withrespect to the direction of said track on which information is to berecorded; and a ring-type magnetic head having a structure with a gap,said gap disposed so as to be inclined in an angular range of from 30degrees to less than 90 degrees with respect to said direction of saidtrack on which information is to be recorded.